Here is what I have done to make my Dillon powder measures throw more consistent charges with all powders. Not just coarse grained powders like Varget, 4198, ect…
First remove the plastic hopper from the measure. If its yellow and cracked, order a new one.
If you look inside you see how rough the inside of the measure is. Its just a aluminum casting.
I start by hitting the inside with some 440 wet/dry sandpaper to take off the high spots. I also break the edge where the hole is in the bottom. Then I fire up the Foredom (AKA Dremel) and start polishing. I use a small Scrotchbrite wheel for the majority of the work. After it starts looking better, I start up with the felt tips and polishing rouge. Once it looks like a good mirror finished feed ramp, I apply some car polish. Several coats just to make sure it stays pretty and more importantly, slick.
It is a royal pain to get inside the track where the adjustment bar slides, but it seems to help. Using a piece of flatbar, I just knock off the highspots with some 440 sandpaper. Then using a large diameter felt wheel, I polish the bottom and left (side away from lever linkage) side. Just polish, don’t remove any metal. Try as I might, my camera wont focus that close.
A big part of adjustment repeatability is the addition of the Uniquetek adjustment knob. With absolutely zero backlash, turning it to X.XX on the dial equals what it did the last time you used it there. Before installing the Uniquetek, I polish the powder bar also. I lightly break the sharp edges on the corners. Try not to remove much metal. Just get it slick. Don’t forget to polish the little notch where the square plastic washer rides. Once installed, consider adding a *very* small amount of grease on the backside of the washer. Probably cant hurt, might help. Here is what the measure looks like with the Uniquetek installed.
I have a grounding wire running from my 1050s to an outlet to keep the whole machine grounded. I also keep anti static spray close by if I see powder sticking to the side of the measure. Some guys tape a static cling sheet to the outside of the powder hopper, but then I cant see how much powder I have left…
I also polish the inside of the powder funnel that rides inside the powder die and also where the powder flows through the measure itself. If it is for 223 or another case where compressed charges are likely, I heavily polish the hole and make it as much of a taper as I possibly can. This allows the powder go in the case faster and keeps spilling down to a dull roar. With a good taper and polish job, I can throw 27.0 gns of Varget in a Lake City 223 case without occasional spilling. Before, 26.6-ish was about it.
Don’t forget to grease the outside rear of the measure where it rides up and down. That is the only place where grease/oil/beeswax *should* be used.
After doing all this, I can throw 10 charges of Varget and only have a 0.2 (0.3 on a bad day) variance, 0.1 either side of the desired weight.
As a technique, I pull the handle down somewhat fast and smooth, stopping abruptly at the bottom of the stroke. Every time. This keeps the powder settled so even amounts get dropped. I go up much slower as I am using an auto indexing machine.
I don’t use any graphite or other dry lubes on the powder bars. It can build up and make the powder bar bind. Gunpowder has enough graphite-ish stuff in it to keep things moving.
Don’t leave powder in your hoppers, it attracts moisture and can klump up leading to powder “jams.” Fine grained pistol powders are really bad about this. Ask me how I know.
Lastly, I hate the Dillon low powder sensors and powder check dies and don’t recommend them.